[web2py] PicklingError: Can't pickle : it's not the same object as Foo

[MikeEllis]

The class isn't really named Foo, of course, but it makes for a more
readable subject line.

Here's the actual ticket:

Traceback (most recent call last):
  File "/Users/mellis/web2py/gluon/main.py", line 504, in wsgibase
    session._try_store_on_disk(request, response)
  File "/Users/mellis/web2py/gluon/globals.py", line 375, in
_try_store_on_disk
    cPickle.dump(dict(self), response.session_file)
PicklingError: Can't pickle <class
'applications.peertool.modules.PTProblemClass.Problem'>: it's not the
same object as applications.peertool.modules.PTProblemClass.Problem

And here is a simple default.py that reliably reproduces the error:

import cPickle
PTProblemClass = local_import('PTProblemClass',reload=True)

def mytest():

    ## Create an instance of class Problem and prove that it
    ## can be pickled.
    problem = PTProblemClass.Problem("Just testing ...",ownerid=2)
    filename = 'problem_' + str(problem.uuid)
    PROBLEMFILEPATH =
os.path.join('applications','peertool','private')
    f = open(os.path.join(PROBLEMFILEPATH,filename),'w')
    cPickle.dump(problem,f)
    f.close()

    ## Assign to session.problem and show that it is
    ## an instance of the class
    session.problem = problem
    assert isinstance(session.problem, PTProblemClass.Problem)

    ## Return a message of comfort and cheer
    return dict(message=T("Test completed"))


def index():  ## Unaltered from new app creation
    """
    example action using the internationalization operator T and flash
    rendered by views/default/index.html or views/generic.html
    """
    response.flash = T('Welcome to web2py')
    return dict(message=T('Hello World'))

I've not included the Problem class code. It's proprietary and I'm
reasonably convinced its not part of the problem since there are no
problems pickling (or unpickling) instances of it.

I can reproduce the problem by the following steps:
1. Visit the index page, no ticket.
2. Visit mytest, no ticket
3. Visit index page again, get the ticket.

I'm running web2py 1.74.9.

Anyone know how to solve this?  It's a particularly annoying because
once the error occurs, the entire app is hosed until I visit the site
page and clean the sessions and caches.

Thanks,
Mike